Load control method and apparatus for CDMA cellular system having circuit and packet switched terminals

Abstract

A method for operating a cellular communications system of a type that includes a first type of terminal having real-time transmission needs and a second type of terminal having nonreal-time transmission needs. The method includes the steps of (a) determining at periodic intervals a total amount of capacity required to service the first type of terminals; (b) subtracting the determined amount from a current maximum capacity; and (c) allocating all or some of the remaining capacity, if any, to one or more of the second type of terminals.

What is claimed is: 
     
       1. A method for operating a wireless communications system of a type that comprises a plurality of wireless terminals capable of transmitting packet data and a base station for receiving the packet data, comprising the steps of: establishing a bidirectional control channel between the base station and individual ones of the wireless terminals such that each wireless terminal has its own bidirectional control channel;   for a wireless terminal that has data to transmit to the base station, subsequently establishing a data channel between the base station and the wireless terminal having data to transmit; and   transmitting packets of data from the wireless terminal to the base station over the established data channel under the direction of messages exchanged over the control channel that was established for that wireless terminal, wherein   the step of transmitting is initiated upon an occurrence of at least one of a predetermined number of packets being stored in a memory of the wireless terminal or a packet being stored in the memory for a predetermined period of time.   
     
     
       2. A method for operating a wireless communications system of a type that comprises a plurality of wireless terminals capable of transmitting packet data and a base station for receiving the packet data, comprising the steps of: establishing a bidirectional control channel between the base station and individual ones of the wireless terminals such that each wireless terminal has its own bidirectional control channel;   for a wireless terminal that has data to transmit to the base station, subsequently establishing a data channel between the base station and the wireless terminal having data to transmit; and   transmitting packets of data from the wireless terminal to the base station over the established data channel under the direction of messages exchanged over the control channel that was established for that wireless terminal, wherein   the step of establishing the bidirectional control channel between the base station and one of the wireless terminals occurs before the wireless terminal has a packet of data to transmit.   
     
     
       3. A method as in claim 2, wherein each control channel is a point-to-point channel comprised of a forward control channel from the base station to the associated wireless terminal and a backward control channel from the wireless terminal to the base station. 
     
     
       4. A method as in claim 2, wherein the step of transmitting comprises a preliminary step of sending a transmission request from the wireless terminal to the base station over the control channel. 
     
     
       5. A method as in claim 4, wherein the transmission request comprises information for specifying a desired transmission rate. 
     
     
       6. A method as in claim 4, wherein the step of transmitting comprises a further preliminary step of sending a permission to transmit from the base station to the requesting wireless terminal over the control channel. 
     
     
       7. A method as in claim 6, wherein the permission to transmit is comprised of information for specifying an assigned transmission rate. 
     
     
       8. A method as in claim 2, wherein the wireless terminal operates in one of a Discontinuous Transmission (DTX) mode or a non-DTX mode. 
     
     
       9. A method as in claim 2, wherein the bidirectional control channel between the base station and one of the wireless terminals remains established during pauses in packet data transmission. 
     
     
       10. A method as in claim 2, wherein each of the channels has an associated spreading code. 
     
     
       11. A method for operating a wireless communications system of a type that comprises a plurality of wireless terminals capable of transmitting packet data and a base station for receiving the packet data, comprising the steps of: establishing a bidirectional control channel between the base station and individual ones of the wireless terminals such that each wireless terminal has its own bidirectional control channel;   for a wireless terminal having no packet data to transmit to the base station, operating in a control channel hold state wherein the control channel remains established;   for a wireless terminal that has data to transmit to the base station, transitioning from the control channel hold state to a state wherein a data channel is established between the base station and the wireless terminal; and   transmitting at least one packet of data from the wireless terminal to the base station over the established data channel under the direction of messages exchanged over the control channel that was established for that wireless terminal, wherein   the step of transitioning from the control channel hold state is initiated upon an occurrence of at least one of a predetermined number of packets being stored in a memory of the wireless terminal or a packet being stored in the memory for a predetermined period of time.   
     
     
       12. A method for operating a wireless communications system of a type that comprises a plurality of wireless terminals capable of transmitting packet data and a base station for receiving the packet data, comprising the steps of: establishing a bidirectional control channel between the base station and individual ones of the wireless terminals such that each wireless terminal has its own bidirectional control channel;   for a wireless terminal having no packet data to transmit to the base station, operating in a control channel hold state wherein the control channel remains established;   for a wireless terminal that has data to transmit to the base station, transitioning from the control channel hold state to a state wherein a data channel is established between the base station and the wireless terminal; and   transmitting at least one packet of data from the wireless terminal to the base station over the established data channel under the direction of messages exchanged over the control channel that was established for that wireless terminal, wherein   the step of establishing the bidirectional control channel between the base station and at least one of the individual ones of the wireless terminals occurs before the at least one wireless terminal has a packet of data to transmit.   
     
     
       13. A method as in claim 12, wherein each control channel is a point-to-point channel comprised of a forward control channel from the base station to the associated wireless terminal and a backward control channel from the wireless terminal to the base station. 
     
     
       14. A method as in claim 12, wherein the step of transitioning from the control channel hold state comprises a step of sending a transmission request from the wireless terminal to the base station over the control channel. 
     
     
       15. A method as in claim 14, wherein the transmission request comprises information for specifying a desired transmission rate. 
     
     
       16. A method as in claim 14, wherein the step of transitioning comprises a further step of sending a permission to transmit from the base station to the requesting wireless terminal over the control channel. 
     
     
       17. A method as in claim 16, wherein the permission to transmit is comprised of information for specifying an assigned transmission rate. 
     
     
       18. A method as in claim 12, wherein the wireless terminal operates in one of a Discontinuous Transmission (DTX) mode or a non-DTX mode. 
     
     
       19. A method as in claim 12, wherein the bidirectional control channel between the base station and one of the wireless terminals remains established during pauses in packet data transmission. 
     
     
       20. A method as in claim 12, wherein each of the channels has an associated spreading code. 
     
     
       21. A wireless communications system of a type that comprises a plurality of wireless terminals capable of transmitting packet data and a base station for receiving the packet data, comprising: means for establishing a bidirectional control channel between the base station and individual ones of the wireless terminals such that each wireless terminal has its own bidirectional control channel;   for a wireless terminal having no packet data to transmit to the base station, a control means for operating the wireless terminal in a control channel hold state wherein the control channel remains established;   for a wireless terminal that has data to transmit to the base station, said control means operating to transition the wireless terminal from the control channel hold state to a state wherein a data channel is established between the base station and the wireless terminal; and   means for transmitting at least one packet of data from the wireless terminal to the base station over the established data channel under the direction of messages exchanged over the control channel that was established for that wireless terminal, wherein   the means for transmitting operates in response to an occurrence of at least one of a predetermined number of packets being stored in a memory of the wireless terminal or a packet being stored in the memory for a predetermined period of time.   
     
     
       22. A wireless communications system as in claim 21, wherein each control channel is comprised of a point-to-point channel comprised of a forward control channel from the base station to the associated wireless terminal and a backward control channel from the wireless terminal to the base station. 
     
     
       23. A wireless communications system as in claim 21, wherein the control means operates, when transitioning from the control channel hold state, to send a transmission request from the wireless terminal to the base station over the control channel, the transmission request comprising information for specifying a desired transmission rate, and further operates to receive a permission to transmit from the base station over the control channel, the permission to transmit comprising information for specifying an assigned transmission rate.